The present invention relates generally to trickle-flow irrigation valves, and, more particularly, to such valves which are installable through the wall of a water pipe or garden hose.
As is well known, it is often desirable to provide irrigation at relatively low flow rates in the order of a gallon per hour from each of a number of outlets in a common supply line, and at relatively low pressure, so that spraying does not occur. To achieve uniformity in the flow rates from the several outlets, a relatively high supply pressure is needed. This, in turn, necessitates extremely small discharge orifices at the outlets, and clogging of the outlets is therefore a significant problem. Furthermore, uniformity of flow rates cannot be attained, of course, without some form of pressure regulation.
Various trickle-flow irrigation valves have been proposed, and some of these address the clogging problem to some degree by providing flushing operations implemented in various ways. It is highly desirable in trickle-flow irrigation valves of this general type to provide for both an automatic flushing operation on turn-on of the water supply, and a manual flushing operation which can be actuated as needed in the field. In addition, an uncomplicated and easily dissassembled construction are definite and desirable advantages.